Last month over 20 malware-infected apps made their way into Apple's App Store, so it's no surprise to see the American company take some increased security measures. On Thursday, the iPhone maker removed several apps from its store after they were deemed potentially invasive to user privacy.

The apps in question largely employ ad-blocker functions, achieved in these cases by the installation of root certificates, which allows for in-app protection against ads. However, it also allows for various third parties to gain access to the user's private information.

"We've removed a few apps from the App Store that install root certificates which enable the monitoring of customer network data that can in turn be used to compromise SSL/TLS security solutions," an Apple spokesperson said. "We are working closely with these developers to quickly get their apps back on the App Store, while ensuring customer privacy and security is not at risk."

The move comes around three weeks after over two dozen infected Chinese apps made their way into the App Store. These tainted applications, which included an older version of the widely used WeChat messenger, were produced by developers who were unaware that they were using a counterfeit version of Xcode, the program used to make apps for iOS. That was the biggest breach ever into Apple's tightly-controlled App Store.

The developers are not thought to have acted maliciously, with Apple working to get new versions of the removed apps back into the Store. Programs which install root certificates are able to monitor a user's activity on the Internet, with data on their communications and even finances being sent to he app's servers, where it can potentially be monitored by developers or network providers.

Apple did not specify how many or which apps were removed, though content-blocker Been Choice revealed on Twitter revealed that it was among them, and is working to resubmit a re-worked app that complies with Apple's security standards.